How do Southern Baptists who believe in the immortality of the soul explain what death means in scripture

The Bible often speaks of death as "sleep" and Ecclesiastes 9:5 says dead aren't aware of anything. Yet many Christians claim reward or punishment begins immediately when one dies. If there is really no death, but just immediate transformation from physical to spiritual beings what is death? Why do these same Christians speak about the resurrection which means standing back up to life? I would like a Southern Baptist perspective.